Acquired flat feet can develop from a specific injury (trauma) and cumulative trauma (repetitive or overuse injuries). In these cases, people are born with flat feet, but the condition is not evident until ages 5–6 when the normal foot arch is supposed to develop but doesn't. There are two categories of flat feet causes: congenital and acquired. However, people with flat feet tend to pronate excessively, a process called overpronation. Pronation involves the outside of the foot's sole contacting the surface first, then the foot rolls, and the medial side contacts the surface. Thus, flat feet mean a lack of curvature of the medial arch, called the medial longitudinal arch since it is on the medial side and longitudinal (lengthwise).Īlso, during normal walking, the foot undergoes pronation - rolls inward - for shock-absorbing reasons. If you notice on the imprints in the picture, the foot's outside area (lateral side) is the same for normal and flat feet, the difference is on the medial (middle) side. If you're curious if you have a flat foot, you can look at the imprint your foot makes on the floor after getting out of a pool or shower - the flat foot will leave more of a water imprint than a normal arched foot. Treatment of pes planus usually involves treating the symptoms, including orthotics, arch supports, physical therapy, medications, and surgical treatment (in rare cases).Īs seen in the image, the foot on the left has a normal arch, while the one on the right is a foot with a flat arch.

What does it mean to be flat footed